JPH0454186B2 - - Google Patents

Abstract

An apparatus for electronically testing printed circuit boards or the like includes a plurality of substantially parallel test pins for making electrical contact between resilient contact elements in an array plate or the like and contact areas on a printed circuit board. A mask plate extends at right angles to the test pins and has through-bores through which the test pins extend in a manner such that one end of each test pin projects therethrough to engage a respective contact area of a circuit board placed in a testing position. Spaced from the mask plate is an elastic plate which is substantially parallel to the mask plate and which receives test pins, which are non-yielding or rigid longitudinally, in a manner such that such pins are retained in the elastic plate due to the elasticity of the material thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a contact portion of a test object such as a printed circuit board and a plurality of resilient contacts arranged according to a complete grid of an array plate or the like. an electronic test device, such as a printed circuit board, comprising a plurality of substantially parallel test pins for forming electrical contact with one of the parts, the device being pressed against the printed circuit board; A board is arranged at right angles to the test pin, and the test pin passes through the through hole of the mask board, and the chip part is connected to a contact part of a printed circuit board or the like placed at a predetermined position. This relates to testing equipment for printed circuit boards, etc.

[Prior Art] West German Patent Application (DE-OS) No. 2933682 discloses a method for forming an electrical contact between an array of contact points on a basic grid and a printed circuit board pressed against an electrical test device. A printed circuit board electronic testing device or adapter is disclosed that includes pins for testing the elasticity of a printed circuit board. Each test pin has a tip opposite the contact array for coupling a guide channel of the device with the contact array, and connects the rigid contact element connected by the guide channel to the electronic test device. During testing, on opposite edges of the printed circuit board,
The test pin is provided with a longitudinally elastic contact tip for mating with a pad connected to a through-hole in a printed circuit board pressed into the test device so as to make electrical contact with the pad. There is.

Problems to be Solved by the Invention One of the disadvantages of test pins of this nature is that the longitudinally elastic contact tip is relatively complex and expensive. Also, the resilient contact tip portion of the tip is relatively large. This becomes more complex and inconvenient as printed circuit board packing densities increase, and the average contact point density on the basic grit of the contact array locally increases the contact pad density. It can also lead to overdoing it. The relatively large diameter of the test pin in the area of the elastic contact tip precludes its applicability in the case of high pad densities.

Also, each test pin does not have an elastic contact tip,
Alternatively, structures or adapters in which each contact element of the grit-aligned connection point array is itself elastic are also well known. A disadvantage of this method is that the springless test pin must be contoured around its outer circumference in order to be held vertically in the device. Such an undulating profile can be created, for example, by increasing the diameter of the tip of the test pin in predetermined areas. The larger diameter limits the possibility of adapting the overall structure to higher pad densities on the edges of printed circuit boards. On the other hand, such an undulating profile can also be obtained in part by reducing the diameter of the test pinch tip. However, in this case the stability of the test pinch tip would be compromised.

[Problems to be Solved by the Invention] In view of the above-mentioned problems, the present invention constitutes an apparatus as described above that can use a test pin without a spring and without forming an undulating profile. The purpose is to

[Means for Solving the Problem] This purpose is to provide an electronic testing device for printed circuit boards, etc., as described above, by using an elastic plate arranged in parallel with a distance from the mask plate. This is accomplished by an electronic test device, such as a printed circuit board, with test pins passing through an elastic plate such that the test pins are held by the inherent elasticity of the material of the plate.

One essential advantage of the present invention is that springless, non-contoured, or solid test pins can be used.

The cost of such sturdy pins is about 90% to 95% less than making elastic test pins, and about 70% less than making pins without contoured external contours.

In addition, the structural cost of test pins is very low, so
There is also the advantage that devices or adapters of the present invention can be economically stocked as arranged in a particular printed circuit board layout. Once assembled, the device or adapter does not need to be disassembled and is ready for future use.

The non-contoured test pin of the present invention does not require a portion whose diameter is smaller than the diameter of the surface needed to form the connection. As a result, the diameter is only the dimension of the connecting surface that ultimately determines the stability of the test pin.

Another advantage of the invention is that the ends of the test pins are provided with heads, such heads having the desired configuration, which can be the same at both ends. This allows the test pin to be manufactured in the most cost effective manner.

Embodiment FIG. 1 shows in a simplified diagram an embodiment of a device 1 for electronically testing, such as a printed circuit board, according to the invention. This device basically consists of a mask plate 3, an elastic plate or insertion plate 4 extending parallel to the mask plate 3 and spaced apart from the mask plate 3, and holding the mask plate 3 and the elastic plate 4 at a desired distance. As shown in the figure, two spacers 7 and 8 extending perpendicularly to the plane of the plate, a test pin 2 extending perpendicularly to the elastic plate 4, and an array plate 12 with a grit array are provided with the apparatus. A preferred spacing adapter 9 is provided which is arranged on the surface of the mask plate 3 opposite to the elastic member 11 and the elastic plate 4 and is slightly thicker than the thickness of the circuit board 1 to be tested.

The array plate 12 is attached at a connection 13 at each grid point;
is shown schematically in the figure, but is elastic in the longitudinal direction. The structure of the connecting portion 13 is shown in more detail in FIG. The test pins 2 form a connection between a given connection 13 and a feed-through or connection pad of a given printed circuit board 1. For simplicity, FIG. 1 shows only one test pin 2. The test pins 2 extend through through holes 14 in the mask plate 3, preferably made of plastic glass (trade name Plexiglass). The feedthroughs or connection pads of the printed circuit board 1 are connected to the array board 12.
If it corresponds to a grid, then the through holes 14 are also aligned with that grid. If the connecting pads or vias of the printed circuit board 1 do not correspond to the alignment grid, the through holes 14 are arranged to match the distribution pattern of the vias or vias. The elastic plate 4 is tightly coupled around the test pin 2 to prevent the test pin 2 from coming off and falling from the test device. The elastic plate 4 is constructed to be sufficiently stable and has the necessary elasticity so that it can be mounted on the device as a stable plate. The elasticity of the plate 4 exerts an elastic pressure on the circumferential surface of the test pin 2, and the pin is held firmly and immobile by the material of the plate 4 surrounding it. The relatively stiff elastic plate 4 is preferably made of an elastic polymeric material, in particular a moderately reinforced foam. Plate 4 includes spacers 7 and 8 and pressure plate 1
6 is mounted on the spacers 7, 8 by means of fixing means such as 15 screwed together. The pressure plate 16 also operates to elastically press the elastic plate 4 against the opposite ends of the spacers 7,8. The mask plate 3 is also attached to the spacer 7 by a similar screw attachment member 17.
It is preferable to fix it to 8. In addition, the legs of such a screw attachment member pass through the holes in the mask plate 3,
The head of each screw attachment member 17 also extends axially beyond the end portion of the associated hole to act as the spacing adapter 9 described above.

The elastic member 11 consists of a helical spring or a block made of elastic material, and is arranged on the array plate 1.
It is provided at the ends of the spacers 7 and 8 adjacent to the spacers 2 and 2. Preferably, at least one elastic member 11 is provided at each end of the spacer 7,8. The operation of this elastic member will be explained in detail below.

The aforementioned device has a corresponding through hole 14 in the mask plate 3.
The test pin 2 is loaded by inserting one test pin 2 into the connecting portion 1 of the array plate 12.
3 and the through-holes or connection pads of the printed circuit board 1.
As described above, the test pin inserted in this manner is held by an elastic plate 4 having a firm outer peripheral surface so that the test pin does not fall out of the device. To facilitate proper insertion of the pins 2 for a particular test into the elastic plate 4, a template or master form (not shown) is provided, which has openings corresponding to the grids of the array plate 12. It is being Such a prototype is placed on an elastic plate 4 in order to insert test pins 2 into predetermined positions.

FIG. 2 shows a further developed embodiment of the invention. In FIG. 2, the aforementioned prototype is placed on the spacers 7, 8 in the aforementioned positions and replaced by an elastic plate or guide plate 5 parallel to the insert 4. Such a top guide plate 5 is provided with through holes 10 corresponding to the full grit of the array plate 12 for receiving the individual test pins 2 therethrough when the device is loaded. The top guide plate 5, whose through holes 10 correspond to a grid pattern, is fixed to the spacers 7, 8 by means of screw attachment members 15, which have been described above in connection with FIG. Also, through holes can be provided in the top guide plate 5 corresponding to any part of the grid to accommodate a particular printed circuit board.

A device of this kind, loaded on a test pin 2 for a particular circuit board, is placed on a suitable support medium (not shown in the figure) in an inverted position, with the elastic plate 4 located at the top. It can thereby be stored for future use. By using such a method and by retaining it in the elastic plate 4, the test pin 2 cannot fall out of the device even if the elastic plate 4 is not firmly connected to the rest of the device.

FIG. 3 shows a further developed embodiment of the invention. In this embodiment, another guide plate 6 is arranged below the elastic plate or insert 4, the guide plate 6 being provided with a through hole according to the basic grid pattern described above and connected to the mounting member 15 described above. Therefore, it is fixed to the spacers 7 and 8. This information board 6
The through holes 18 correspond to the complete basic grid of the array board 12 or to any portion of that grid to accommodate a particular circuit board 1. In this case, the elastic plate 4 is in the form of a plate or sheet which is arranged loosely in the space between the top and bottom guide plates 5, 6, both of which are arranged in a predetermined basic arrangement grid. are aligned. One advantage of this device is that the elastic plate 4, which is loosely placed between the guide plates 5, 6, can be adapted to accommodate irregularities of the printed circuit board 1, such as occur in normal manufacturing, in the range of the elastic plate 4. Each test pin 2 mutually displaced in the direction
This makes it possible to accommodate irregularities in the circuit board 1. Once the circuit board 1 is removed, such displacements are eliminated by the elastic board 4 which returns to its initial state due to its natural elasticity.

In the assembled structure shown in FIG. 3, the test pin and contact devices for the particular printed circuit board contact configuration are maintained as shown. Further, the elastic plate 4 is held in the space between the guide plates 5 and 6. If the device is supported on the mask plate 3 at the bottom as described above, the guide plate 6 can be removed and used for other purposes.

Each test pin has no head and has no particular undulations on its outer circumferential surface. Rather, the test pin may have the same shape at both ends so that the test pin 2 is completely symmetrical. This further reduces their manufacturing cost. The test pin 2 is made of an elastic, bendable material, preferably an elastic, flexible copper spring material.

The tip of each test pin 2 is frustoconical as shown in FIGS. 4-6. The tip shape of such a test pin has the advantage of being able to contact both the feed-through contacts of the printed circuit board and the connection pads of the SMD circuit board. As shown in FIG. 5, the tip of each test pin 2 has a truncated conical shape. A contact is made between the flat end faces of the chip or along the tapering peripheral line 19 of the chip to the through hole 24 of the circuit board 1. A truncated conical test pin of this type was used as the fifth
When the connecting pad 20 is brought into contact as shown in the figure,
The end face 21 mates with the surface of the connecting pad 20 of the printed circuit board 1. Since the end face 21 influences the surface pressure, the surface finish (gold coating) of the connecting pad 20 is not mechanically destroyed. If the tip of the test pin 2 is not flat, such breakage is likely to occur due to the pressure generated during the test.

The contact surface 22 of the contact portion 13 of the well-known structure of the array plate 12 is funnel-shaped to easily remove dirt caused by the peripheral portion of the test pin 2 rubbing along the inner wall of the through hole 18 of the bottom guide plate 6. Trap. If a sharp tip is used with the test pin 2, dirt that accumulates at the bottom of the funnel-shaped contact surface 22 will be transferred to the surface 2.
Push the tip up from 2 to cut off contact. If the tip has the above-mentioned truncated conical shape, the contact will be reliable even if the contact portion 13 is dirty. This is because the edge 23 between the flat end face 21 and the tapered part of the tip contacts the funnel-shaped surface in such a way that it is annularly shaped. Such annular contact occurs above the apex of the funnel-shaped surface 22. The edge-type contact along the annular edge 23 substantially increases the safety of the contact over the use of a sharp tip. The tip of the test pin 2 has a frusto-conical end and does not always enter the contact area 13 in a completely vertical direction, so that the contact area is essentially a funnel-shaped surface 22 and statistically cluttered. take position. the result,
The life of both the contact 13 and the test pin 2 is increased considerably. The force distribution obtained by flattening the end face can be controlled by the dimensions of the end face.

If the test pin 2 is made of spring steel, it exhibits maximum flexibility. After bending, the elasticity of the test pin returns it to its initial axial position. These elastic bends occur to accommodate the geometry of the plate or board and create connections between the basic grid of the array plate 12 and the connections or pads of the circuit board 1 outside that grid. can be done. In addition, in the case of a local collection of connection points on the circuit board 1 that is denser than the basic grid of the array board 12, it is possible to compensate by means of the test pins 2 or their bent groups, and the length of the test pins This bending occurs without changing the

In order to limit potential bending of the test pin 2, the spacers 7, 8 are provided with through holes arranged at right angles to the axis of the test pin 2 and in locations where the test pin is expected to bend. intermediate plate 30 having 31
is placed. Such an intermediate plate 30 is shown in FIG. 1 by dashed lines. The through holes 14 of the mask plate 3 are aligned with the grid of the array plate 12, and the through holes of said intermediate plate are aligned with that grid. On the other hand, if the through holes 14 of the mask plate 3 are not aligned with the grid of the array plate 14, the through holes of the intermediate plate are misaligned;
They are arranged with respect to each other in such a way that they arrive at the grid of the arrangement plate 12 with gradual changes.

The device is then positioned relative to the printed circuit 1 for testing. Such a device has a force F1 (third
A pressure plate 23 is provided in order to exert a force (FIG.), the force of which is transmitted directly to the spacers 7, 8 via the spacing adapter component 9. Force F1 is opposed by force F2 exerted by resilient medium 11. On the other hand, the force F1 is transmitted to the circuit board 1, and from the circuit board 1 to the test pin 2. Contact portion 13 having elasticity
produces a force F3 in the opposite direction through the test pin 2. Adapter part 9 on circuit board 1 and spacers 7 and 8
Due to the overall force F1 of the pressure plate 23 acting through the spacers 7, 8 and the components connected thereto, the test pin 2 is brought into contact with elasticity by the same distance as the spacers 7, 8 and the components connected thereto. The power of 13 F3
be moved against. No relative movement occurs between the test pin 2, the mask plate 3, the intermediate plate 30, and the guide plates 5, 6. The mask plate 3, the intermediate plate 30, and the guide plates 5, 6 receive friction from the inner walls of the through hole 14 of the mask plate 3, the through hole 31 of the intermediate plate 30, and the through holes 10, 18 of the top and bottom guide plates 5, 6, respectively. The material is pulled apart by the

By means of an elastic plate, sheet or insert plate to which the outer circumferential surfaces of the test pins are closely connected, dirt on the top surface and similar through the holes in the mask plate, intermediate plate and top plate can be tested. The top surface prevents particles such as dust from falling from the printed circuit board inside.

If the elastic plate 4 is made of a hard foam material, holes may be provided to receive the test pins 2.

The flat test pin 2 used in this device is particularly suitable for use in automatic CAF systems since there are no noticeable undulations, making the pin easy to grasp. The CAF (computer assisted fixation) system operates to determine from the perforation data available for individual circuit boards, as well as the perforation data available for mask boards or the perforation data available for gridded guide plates. When automatic test pin loading equipment is used, loaded data is determined from the drill data available for each circuit board.

[Brief explanation of the drawing]

1-3 are schematic diagrams of embodiments of the invention, FIG. 4 shows the tip of the test pin contacting the through-hole in the printed circuit board, and FIG. FIG. 6 shows the tip of the test pin in contact with the funnel-shaped opening of the contact portion of the grid arrangement. 1... Printed circuit board, 2... Test pin, 3... Mask board, 4... Elastic board, 5, 6... Guide plate, 7,
8...Spacer, 12...Array plate, 13...Contact portion, 14...Through hole, 30...Intermediate plate.

Claims (1)

Claims: 1. Forming an electrical contact between a contact portion of a test object, such as a printed circuit board, and one of a plurality of resilient contact portions arranged according to a complete grid of an array plate or the like. An electronic testing device, such as a printed circuit board, comprising a plurality of substantially parallel test pins for testing,
The device is pressed against the printed circuit board, the mask plate is placed at right angles to the test pins, and the test pins pass through the holes in the mask plate to place the chip portions in predetermined positions. In a test device for a printed circuit board, etc., which is connected to a contact part of a printed circuit board, etc., the test pin, which is not elastic in the longitudinal direction, is connected to the elastic plate by an elastic plate arranged parallel to the mask plate at a distance from the mask plate. An electronic testing device for a printed circuit board or the like, characterized in that the device extends through the elastic plate so as to be held by the inherent elasticity of the material. 2. The device of claim 1, wherein the through holes in the mask plate correspond to or are not aligned with the basic grid of the array plate. 3. Claim 1 or 2, characterized in that the test pin is a pin with no undulations on its outer peripheral surface.
Apparatus described in section. 4. Claim 1, characterized in that each test pin is made of elastically bendable spring steel.
The device according to any one of items 1 to 3. 5. A spacing adapter is provided between the mask plate located on the opposite side of the printed circuit board and a pressure surface that presses the printed circuit board against the chip of the test pin, and this spacing adapter is connected to the printed circuit board. having a thickness approximately corresponding to the thickness of An apparatus according to any one of claims 1 to 4. 6. The device according to claim 5, wherein the mask plate and the elastic plate are kept apart from each other by spacers, and the spacing adapter is fixed to one end of each spacer. 7. Apparatus according to claim 6, characterized in that an elastic member is provided at the other end of each spacer, and the test device is pressed against the array plate against the force generated by the elastic member. . 8. Device according to claim 7, characterized in that the elastic member comprises a helical spring. 9. Device according to claim 7, characterized in that the elastic member is made of an elastic material. 10. Apparatus according to any one of claims 1 to 9, characterized in that at least one of the ends of each test pin is frustoconical. 11. A top guide plate is provided on the mask plate side of the elastic plate and is provided with through holes for the test pins, and that the through holes are provided according to the entire elementary grid of the array plate or a preselected part of said grid. A device according to any one of claims 1 to 10, characterized in that: 12 Claim 11, characterized in that the elastic plate and the top guide plate are attached to the spacer.
Apparatus described in section. 13 Claim 11, characterized in that the elastic plate and the top guide plate are attached to the spacer.
13. The device according to item 1 or 12. 14. A bottom guide plate is provided at a distance from the top guide plate and is provided with through holes for test pins according to the entire elementary grid of the array plate or a preselected portion of said grid, said elastic plate being spaced apart from the top guide plate. Claims 11 to 13 are characterized in that the elastic insertion part is sandwiched between the bottom guide plate and the bottom guide plate.
Apparatus according to any one of paragraphs. 15. Device according to claim 14, characterized in that the thickness of the elastic insert is less than the distance between the top and bottom guide plates. 16. Device according to any one of claims 1 to 15, characterized in that the elastic plate or the insert part is made of a hard foam-like material or rubber. 17 The mask plate is fixed to the spacer by fixing means such as bolts, the legs of each fixing means such as bolts are fixed to the spacer through holes provided in the mask plate, and the spacing adapter is attached to the bolts etc. 17. Device according to any one of claims 5 to 16, characterized in that it is formed by the head of a fixing means. 18 Claims 1 to 17, characterized in that the mask plate is made of plastic glass.
The device according to any one of paragraphs. 19 At least one intermediate plate is arranged parallel to the mask plate between the mask plate and the elastic plate or the top guide plate, this intermediate plate being an array plate if the pattern of the through holes of the mask plate corresponds to the basic grid. with through holes arranged according to the basic grid of
Claims 1 to 18, characterized in that a mask plate that is not aligned with the basic grid of the array plate is provided with through holes arranged so as to be gradually displaced from the basic grid of the array plate to the through holes. The device according to any one of paragraphs.